Spectrum ROM: Routine at 13759

13759: THE 'STK-PNTRS' SUBROUTINE

Used by the routines at CALCULATE, strs_add, val and read_in.

This subroutine resets the HL register pair to point to the first byte of the 'last value', i.e. STKEND-5, and the DE register pair to point one past the 'last value', i.e. STKEND.

Output
DE	STKEND
HL	STKEND-5

STK_PNTRS

13759

LD HL,(23653)

Fetch the current value of STKEND.

13762

LD DE,65531

Set DE to -5, two's complement.

13765

PUSH HL

Stack the value for STKEND.

13766

ADD HL,DE

Calculate STKEND-5.

13767

POP DE

DE now holds STKEND and HL holds STKEND-5.

13768

RET